[libc-commits] [libc] [libc][NFC] Rename MAX_EXPONENT to MAX_BIASED_EXPONENT (PR #75932)
Guillaume Chatelet via libc-commits
libc-commits at lists.llvm.org
Tue Dec 19 05:58:26 PST 2023
https://github.com/gchatelet created https://github.com/llvm/llvm-project/pull/75932
None
>From 2f85b38f0a41ea6b71e5150d9dcaddf9860561ad Mon Sep 17 00:00:00 2001
From: Guillaume Chatelet <gchatelet at google.com>
Date: Tue, 19 Dec 2023 13:58:03 +0000
Subject: [PATCH] [libc][NFC] Rename MAX_EXPONENT to MAX_BIASED_EXPONENT
---
libc/src/__support/FPUtil/FPBits.h | 4 +--
libc/src/__support/FPUtil/Hypot.h | 4 +--
.../__support/FPUtil/ManipulationFunctions.h | 2 +-
libc/src/__support/FPUtil/generic/FMA.h | 8 +++---
.../__support/FPUtil/x86_64/LongDoubleBits.h | 16 ++++++------
libc/src/__support/high_precision_decimal.h | 4 +--
libc/src/__support/str_to_float.h | 26 +++++++++----------
libc/test/src/math/LdExpTest.h | 11 ++++----
libc/test/src/math/smoke/LdExpTest.h | 11 ++++----
.../utils/FPUtil/x86_long_double_test.cpp | 2 +-
10 files changed, 45 insertions(+), 43 deletions(-)
diff --git a/libc/src/__support/FPUtil/FPBits.h b/libc/src/__support/FPUtil/FPBits.h
index 7f5dd0fca58d4f..14800c2ccce830 100644
--- a/libc/src/__support/FPUtil/FPBits.h
+++ b/libc/src/__support/FPUtil/FPBits.h
@@ -89,13 +89,13 @@ template <typename T> struct FPBits : private FloatProperties<T> {
static_assert(sizeof(T) == sizeof(StorageType),
"Data type and integral representation have different sizes.");
- static constexpr int MAX_EXPONENT = (1 << EXP_LEN) - 1;
+ static constexpr int MAX_BIASED_EXPONENT = (1 << EXP_LEN) - 1;
static constexpr StorageType MIN_SUBNORMAL = StorageType(1);
static constexpr StorageType MAX_SUBNORMAL = FRACTION_MASK;
static constexpr StorageType MIN_NORMAL = (StorageType(1) << FRACTION_LEN);
static constexpr StorageType MAX_NORMAL =
- ((StorageType(MAX_EXPONENT) - 1) << FRACTION_LEN) | MAX_SUBNORMAL;
+ ((StorageType(MAX_BIASED_EXPONENT) - 1) << FRACTION_LEN) | MAX_SUBNORMAL;
// We don't want accidental type promotions/conversions, so we require exact
// type match.
diff --git a/libc/src/__support/FPUtil/Hypot.h b/libc/src/__support/FPUtil/Hypot.h
index 1f1cf31c801791..c38a40dfb08984 100644
--- a/libc/src/__support/FPUtil/Hypot.h
+++ b/libc/src/__support/FPUtil/Hypot.h
@@ -193,7 +193,7 @@ LIBC_INLINE T hypot(T x, T y) {
sticky_bits = sticky_bits || ((sum & 0x3U) != 0);
sum >>= 2;
++out_exp;
- if (out_exp >= FPBits_t::MAX_EXPONENT) {
+ if (out_exp >= FPBits_t::MAX_BIASED_EXPONENT) {
if (int round_mode = quick_get_round();
round_mode == FE_TONEAREST || round_mode == FE_UPWARD)
return T(FPBits_t::inf());
@@ -251,7 +251,7 @@ LIBC_INLINE T hypot(T x, T y) {
if (y_new >= (ONE >> 1)) {
y_new -= ONE >> 1;
++out_exp;
- if (out_exp >= FPBits_t::MAX_EXPONENT) {
+ if (out_exp >= FPBits_t::MAX_BIASED_EXPONENT) {
if (round_mode == FE_TONEAREST || round_mode == FE_UPWARD)
return T(FPBits_t::inf());
return T(FPBits_t(FPBits_t::MAX_NORMAL));
diff --git a/libc/src/__support/FPUtil/ManipulationFunctions.h b/libc/src/__support/FPUtil/ManipulationFunctions.h
index 4a475d1e09c499..8ea753564ed227 100644
--- a/libc/src/__support/FPUtil/ManipulationFunctions.h
+++ b/libc/src/__support/FPUtil/ManipulationFunctions.h
@@ -130,7 +130,7 @@ LIBC_INLINE T ldexp(T x, int exp) {
// early. Because the result of the ldexp operation can be a subnormal number,
// we need to accommodate the (mantissaWidht + 1) worth of shift in
// calculating the limit.
- int exp_limit = FPBits<T>::MAX_EXPONENT + FPBits<T>::FRACTION_LEN + 1;
+ int exp_limit = FPBits<T>::MAX_BIASED_EXPONENT + FPBits<T>::FRACTION_LEN + 1;
if (exp > exp_limit)
return bits.get_sign() ? T(FPBits<T>::neg_inf()) : T(FPBits<T>::inf());
diff --git a/libc/src/__support/FPUtil/generic/FMA.h b/libc/src/__support/FPUtil/generic/FMA.h
index 0180cd56ddef08..c70069487d99aa 100644
--- a/libc/src/__support/FPUtil/generic/FMA.h
+++ b/libc/src/__support/FPUtil/generic/FMA.h
@@ -128,9 +128,9 @@ template <> LIBC_INLINE double fma<double>(double x, double y, double z) {
y_exp += y_bits.get_biased_exponent();
z_exp += z_bits.get_biased_exponent();
- if (LIBC_UNLIKELY(x_exp == FPBits::MAX_EXPONENT ||
- y_exp == FPBits::MAX_EXPONENT ||
- z_exp == FPBits::MAX_EXPONENT))
+ if (LIBC_UNLIKELY(x_exp == FPBits::MAX_BIASED_EXPONENT ||
+ y_exp == FPBits::MAX_BIASED_EXPONENT ||
+ z_exp == FPBits::MAX_BIASED_EXPONENT))
return x * y + z;
// Extract mantissa and append hidden leading bits.
@@ -255,7 +255,7 @@ template <> LIBC_INLINE double fma<double>(double x, double y, double z) {
// Finalize the result.
int round_mode = fputil::quick_get_round();
- if (LIBC_UNLIKELY(r_exp >= FPBits::MAX_EXPONENT)) {
+ if (LIBC_UNLIKELY(r_exp >= FPBits::MAX_BIASED_EXPONENT)) {
if ((round_mode == FE_TOWARDZERO) ||
(round_mode == FE_UPWARD && prod_sign) ||
(round_mode == FE_DOWNWARD && !prod_sign)) {
diff --git a/libc/src/__support/FPUtil/x86_64/LongDoubleBits.h b/libc/src/__support/FPUtil/x86_64/LongDoubleBits.h
index 89c47063ebac4d..e8e57bc86849b2 100644
--- a/libc/src/__support/FPUtil/x86_64/LongDoubleBits.h
+++ b/libc/src/__support/FPUtil/x86_64/LongDoubleBits.h
@@ -38,14 +38,14 @@ template <> struct FPBits<long double> : private FloatProperties<long double> {
using FloatProperties<long double>::QUIET_NAN_MASK;
using FloatProperties<long double>::SIGN_MASK;
- static constexpr int MAX_EXPONENT = 0x7FFF;
+ static constexpr int MAX_BIASED_EXPONENT = 0x7FFF;
static constexpr StorageType MIN_SUBNORMAL = StorageType(1);
// Subnormal numbers include the implicit bit in x86 long double formats.
static constexpr StorageType MAX_SUBNORMAL =
(StorageType(1) << FRACTION_LEN) - 1;
static constexpr StorageType MIN_NORMAL = (StorageType(3) << FRACTION_LEN);
static constexpr StorageType MAX_NORMAL =
- (StorageType(MAX_EXPONENT - 1) << (FRACTION_LEN + 1)) |
+ (StorageType(MAX_BIASED_EXPONENT - 1) << (FRACTION_LEN + 1)) |
(StorageType(1) << FRACTION_LEN) | MAX_SUBNORMAL;
StorageType bits;
@@ -151,12 +151,12 @@ template <> struct FPBits<long double> : private FloatProperties<long double> {
}
LIBC_INLINE constexpr bool is_inf() const {
- return get_biased_exponent() == MAX_EXPONENT && get_mantissa() == 0 &&
- get_implicit_bit() == 1;
+ return get_biased_exponent() == MAX_BIASED_EXPONENT &&
+ get_mantissa() == 0 && get_implicit_bit() == 1;
}
LIBC_INLINE constexpr bool is_nan() const {
- if (get_biased_exponent() == MAX_EXPONENT) {
+ if (get_biased_exponent() == MAX_BIASED_EXPONENT) {
return (get_implicit_bit() == 0) || get_mantissa() != 0;
} else if (get_biased_exponent() != 0) {
return get_implicit_bit() == 0;
@@ -165,7 +165,7 @@ template <> struct FPBits<long double> : private FloatProperties<long double> {
}
LIBC_INLINE constexpr bool is_inf_or_nan() const {
- return (get_biased_exponent() == MAX_EXPONENT) ||
+ return (get_biased_exponent() == MAX_BIASED_EXPONENT) ||
(get_biased_exponent() != 0 && get_implicit_bit() == 0);
}
@@ -177,7 +177,7 @@ template <> struct FPBits<long double> : private FloatProperties<long double> {
LIBC_INLINE static constexpr long double inf(bool sign = false) {
FPBits<long double> bits(0.0l);
- bits.set_biased_exponent(MAX_EXPONENT);
+ bits.set_biased_exponent(MAX_BIASED_EXPONENT);
bits.set_implicit_bit(1);
if (sign) {
bits.set_sign(true);
@@ -189,7 +189,7 @@ template <> struct FPBits<long double> : private FloatProperties<long double> {
LIBC_INLINE static constexpr long double build_nan(StorageType v) {
FPBits<long double> bits(0.0l);
- bits.set_biased_exponent(MAX_EXPONENT);
+ bits.set_biased_exponent(MAX_BIASED_EXPONENT);
bits.set_implicit_bit(1);
bits.set_mantissa(v);
return bits;
diff --git a/libc/src/__support/high_precision_decimal.h b/libc/src/__support/high_precision_decimal.h
index bf33658982c362..d29f8c4cd932f4 100644
--- a/libc/src/__support/high_precision_decimal.h
+++ b/libc/src/__support/high_precision_decimal.h
@@ -344,8 +344,8 @@ class HighPrecisionDecimal {
int64_t temp_exponent = static_cast<int64_t>(this->decimal_point) +
static_cast<int64_t>(add_to_exponent);
- // Theoretically these numbers should be MAX_EXPONENT for long double,
- // but that should be ~16,000 which is much less than 1 << 30.
+ // Theoretically these numbers should be MAX_BIASED_EXPONENT for long
+ // double, but that should be ~16,000 which is much less than 1 << 30.
if (temp_exponent > (1 << 30)) {
temp_exponent = (1 << 30);
} else if (temp_exponent < -(1 << 30)) {
diff --git a/libc/src/__support/str_to_float.h b/libc/src/__support/str_to_float.h
index 9984bcd7064d75..668707efee0c3f 100644
--- a/libc/src/__support/str_to_float.h
+++ b/libc/src/__support/str_to_float.h
@@ -338,7 +338,7 @@ simple_decimal_conversion(const char *__restrict numStart,
// float, return inf.
if (hpd.get_decimal_point() > 0 &&
exp10_to_exp2(hpd.get_decimal_point() - 1) > FloatProp::EXP_BIAS) {
- output.num = {0, fputil::FPBits<T>::MAX_EXPONENT};
+ output.num = {0, fputil::FPBits<T>::MAX_BIASED_EXPONENT};
output.error = ERANGE;
return output;
}
@@ -388,8 +388,8 @@ simple_decimal_conversion(const char *__restrict numStart,
exp2 += FloatProp::EXP_BIAS;
// Handle the exponent being too large (and return inf).
- if (exp2 >= FPBits::MAX_EXPONENT) {
- output.num = {0, FPBits::MAX_EXPONENT};
+ if (exp2 >= FPBits::MAX_BIASED_EXPONENT) {
+ output.num = {0, FPBits::MAX_BIASED_EXPONENT};
output.error = ERANGE;
return output;
}
@@ -424,7 +424,7 @@ simple_decimal_conversion(const char *__restrict numStart,
// Check if this rounding causes exp2 to go out of range and make the result
// INF. If this is the case, then finalMantissa and exp2 are already the
// correct values for an INF result.
- if (exp2 >= FPBits::MAX_EXPONENT) {
+ if (exp2 >= FPBits::MAX_BIASED_EXPONENT) {
output.error = ERANGE;
}
}
@@ -658,7 +658,7 @@ decimal_exp_to_float(ExpandedFloat<T> init_num, const char *__restrict numStart,
// float, return inf. These bounds are relatively loose, but are mostly
// serving as a first pass. Some close numbers getting through is okay.
if (exp10 > get_upper_bound<T>()) {
- output.num = {0, FPBits::MAX_EXPONENT};
+ output.num = {0, FPBits::MAX_BIASED_EXPONENT};
output.error = ERANGE;
return output;
}
@@ -920,10 +920,10 @@ decimal_string_to_float(const char *__restrict src, const char DECIMAL_POINT,
// If the result is in the valid range, then we use it. The valid range is
// also within the int32 range, so this prevents overflow issues.
- if (temp_exponent > FPBits::MAX_EXPONENT) {
- exponent = FPBits::MAX_EXPONENT;
- } else if (temp_exponent < -FPBits::MAX_EXPONENT) {
- exponent = -FPBits::MAX_EXPONENT;
+ if (temp_exponent > FPBits::MAX_BIASED_EXPONENT) {
+ exponent = FPBits::MAX_BIASED_EXPONENT;
+ } else if (temp_exponent < -FPBits::MAX_BIASED_EXPONENT) {
+ exponent = -FPBits::MAX_BIASED_EXPONENT;
} else {
exponent = static_cast<int32_t>(temp_exponent);
}
@@ -1034,10 +1034,10 @@ hexadecimal_string_to_float(const char *__restrict src,
// If the result is in the valid range, then we use it. The valid range is
// also within the int32 range, so this prevents overflow issues.
- if (temp_exponent > FPBits::MAX_EXPONENT) {
- exponent = FPBits::MAX_EXPONENT;
- } else if (temp_exponent < -FPBits::MAX_EXPONENT) {
- exponent = -FPBits::MAX_EXPONENT;
+ if (temp_exponent > FPBits::MAX_BIASED_EXPONENT) {
+ exponent = FPBits::MAX_BIASED_EXPONENT;
+ } else if (temp_exponent < -FPBits::MAX_BIASED_EXPONENT) {
+ exponent = -FPBits::MAX_BIASED_EXPONENT;
} else {
exponent = static_cast<int32_t>(temp_exponent);
}
diff --git a/libc/test/src/math/LdExpTest.h b/libc/test/src/math/LdExpTest.h
index 5c144add3a4a3d..371654e69c3d54 100644
--- a/libc/test/src/math/LdExpTest.h
+++ b/libc/test/src/math/LdExpTest.h
@@ -58,7 +58,8 @@ class LdExpTestTemplate : public LIBC_NAMESPACE::testing::Test {
}
void testOverflow(LdExpFunc func) {
- NormalFloat x(FPBits::MAX_EXPONENT - 10, NormalFloat::ONE + 0xF00BA, 0);
+ NormalFloat x(FPBits::MAX_BIASED_EXPONENT - 10, NormalFloat::ONE + 0xF00BA,
+ 0);
for (int32_t exp = 10; exp < 100; ++exp) {
ASSERT_FP_EQ(inf, func(T(x), exp));
ASSERT_FP_EQ(neg_inf, func(-T(x), exp));
@@ -125,7 +126,7 @@ class LdExpTestTemplate : public LIBC_NAMESPACE::testing::Test {
// Start with a normal number high exponent but pass a very low number for
// exp. The result should be a subnormal number.
x = NormalFloat(FPBits::EXP_BIAS, NormalFloat::ONE, 0);
- int exp = -FPBits::MAX_EXPONENT - 5;
+ int exp = -FPBits::MAX_BIASED_EXPONENT - 5;
T result = func(x, exp);
FPBits result_bits(result);
ASSERT_FALSE(result_bits.is_zero());
@@ -133,17 +134,17 @@ class LdExpTestTemplate : public LIBC_NAMESPACE::testing::Test {
ASSERT_EQ(result_bits.get_biased_exponent(), uint16_t(0));
// But if the exp is so less that normalization leads to zero, then
// the result should be zero.
- result = func(x, -FPBits::MAX_EXPONENT - FPBits::FRACTION_LEN - 5);
+ result = func(x, -FPBits::MAX_BIASED_EXPONENT - FPBits::FRACTION_LEN - 5);
ASSERT_TRUE(FPBits(result).is_zero());
// Start with a subnormal number but pass a very high number for exponent.
// The result should not be infinity.
x = NormalFloat(-FPBits::EXP_BIAS + 1, NormalFloat::ONE >> 10, 0);
- exp = FPBits::MAX_EXPONENT + 5;
+ exp = FPBits::MAX_BIASED_EXPONENT + 5;
ASSERT_FALSE(FPBits(func(x, exp)).is_inf());
// But if the exp is large enough to oversome than the normalization shift,
// then it should result in infinity.
- exp = FPBits::MAX_EXPONENT + 15;
+ exp = FPBits::MAX_BIASED_EXPONENT + 15;
ASSERT_FP_EQ(func(x, exp), inf);
}
};
diff --git a/libc/test/src/math/smoke/LdExpTest.h b/libc/test/src/math/smoke/LdExpTest.h
index 5c144add3a4a3d..371654e69c3d54 100644
--- a/libc/test/src/math/smoke/LdExpTest.h
+++ b/libc/test/src/math/smoke/LdExpTest.h
@@ -58,7 +58,8 @@ class LdExpTestTemplate : public LIBC_NAMESPACE::testing::Test {
}
void testOverflow(LdExpFunc func) {
- NormalFloat x(FPBits::MAX_EXPONENT - 10, NormalFloat::ONE + 0xF00BA, 0);
+ NormalFloat x(FPBits::MAX_BIASED_EXPONENT - 10, NormalFloat::ONE + 0xF00BA,
+ 0);
for (int32_t exp = 10; exp < 100; ++exp) {
ASSERT_FP_EQ(inf, func(T(x), exp));
ASSERT_FP_EQ(neg_inf, func(-T(x), exp));
@@ -125,7 +126,7 @@ class LdExpTestTemplate : public LIBC_NAMESPACE::testing::Test {
// Start with a normal number high exponent but pass a very low number for
// exp. The result should be a subnormal number.
x = NormalFloat(FPBits::EXP_BIAS, NormalFloat::ONE, 0);
- int exp = -FPBits::MAX_EXPONENT - 5;
+ int exp = -FPBits::MAX_BIASED_EXPONENT - 5;
T result = func(x, exp);
FPBits result_bits(result);
ASSERT_FALSE(result_bits.is_zero());
@@ -133,17 +134,17 @@ class LdExpTestTemplate : public LIBC_NAMESPACE::testing::Test {
ASSERT_EQ(result_bits.get_biased_exponent(), uint16_t(0));
// But if the exp is so less that normalization leads to zero, then
// the result should be zero.
- result = func(x, -FPBits::MAX_EXPONENT - FPBits::FRACTION_LEN - 5);
+ result = func(x, -FPBits::MAX_BIASED_EXPONENT - FPBits::FRACTION_LEN - 5);
ASSERT_TRUE(FPBits(result).is_zero());
// Start with a subnormal number but pass a very high number for exponent.
// The result should not be infinity.
x = NormalFloat(-FPBits::EXP_BIAS + 1, NormalFloat::ONE >> 10, 0);
- exp = FPBits::MAX_EXPONENT + 5;
+ exp = FPBits::MAX_BIASED_EXPONENT + 5;
ASSERT_FALSE(FPBits(func(x, exp)).is_inf());
// But if the exp is large enough to oversome than the normalization shift,
// then it should result in infinity.
- exp = FPBits::MAX_EXPONENT + 15;
+ exp = FPBits::MAX_BIASED_EXPONENT + 15;
ASSERT_FP_EQ(func(x, exp), inf);
}
};
diff --git a/libc/test/utils/FPUtil/x86_long_double_test.cpp b/libc/test/utils/FPUtil/x86_long_double_test.cpp
index cea43c1a6fa4d5..7da835fc95fc92 100644
--- a/libc/test/utils/FPUtil/x86_long_double_test.cpp
+++ b/libc/test/utils/FPUtil/x86_long_double_test.cpp
@@ -22,7 +22,7 @@ TEST(LlvmLibcX86LongDoubleTest, is_nan) {
constexpr uint32_t COUNT = 100'000;
FPBits bits(0.0l);
- bits.set_biased_exponent(FPBits::MAX_EXPONENT);
+ bits.set_biased_exponent(FPBits::MAX_BIASED_EXPONENT);
for (unsigned int i = 0; i < COUNT; ++i) {
// If exponent has the max value and the implicit bit is 0,
// then the number is a NaN for all values of mantissa.
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